Solved: Furnace Is Leaking Water and 8 Other Heating Issues

Whether it’s a leaky furnace or if you throw the switch to start your heating system when it gets chilly and it won’t start, common furnace problems can strike your home at any moment.

Regardless of the cause, learning how your heating system works and a little bit about some common furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional assistance. By observing the furnace's behavior, listening for strange noises and checking for signs of damage or blockage, you can narrow down the possible causes.

If you're uncertain about the problem or lack the necessary skills and tools, it's best to call a professional HVAC company like Smyth Air Conditioning. We can accurately pinpoint the issue and execute the required repairs or maintenance, so we can get your furnace working again ASAP.

Here's more about what causes a furnace to leak water and eight other frequent heating issues:

1. My Furnace Is Leaking Water

A furnace can leak water for a number of reasons. One possibility is a condensate leak, where the water produced during the combustion process is not properly draining away. This might be due to a blocked condensate drain line or a failing condensate pump. Another possible cause of water leakage from a furnace is a cracked heat exchanger, which can lead to water—as well as dangerous gases—leaking out of the furnace.

It is important to address water leaks promptly to prevent more damage to your furnace. Consulting with a professional HVAC technician like the crew at Smyth Air Conditioning is recommended to diagnose and resolve the issue successfully.

2. My Furnace Makes Cold Air/Not Blowing Hot Air

Some potential causes for a furnace blowing cold air or not blowing hot air are a malfunctioning thermostat, a problem with the pilot light or ignition system, a plugged air filter, or a malfunctioning heating element. It is also possible your furnace is overheating and shutting off as a safety mechanism.

If your furnace will not blow hot air, it's best to contact a professional HVAC tech to diagnose and fix the problem. They can offer an accurate assessment and advise you on the appropriate solution.

3. My Furnace Struggles to Keep Up

A common reason your furnace isn’t keeping up on a cold day is that your home doesn’t have enough insulation, which can result in heat loss and reduced efficiency. Another reason your furnace is struggling is because it’s too small for your home, so it can’t produce enough heat to adequately warm the space. A defective thermostat or ductwork problems can also cause insufficient heating.

To correct this, first look at your home’s insulation level and make sure it’s enough to keep warm air in and cold air out of your home. Also, check the thermostat to see if it’s set right and the batteries are working.

If the problem continues, consider calling an experienced HVAC company, such as Smyth Air Conditioning, who can assess your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or adjusting your thermostat settings.

4. My Furnace Is Not Working

If your furnace is not working, there are a couple of steps you can take to troubleshoot before contacting a pro. Check if the thermostat is set properly and the batteries are good. If the furnace still doesn't start, check the circuit breaker or fuse box to verify power is reaching the furnace.

If there is power but your furnace won't ignite, the problem may be with the ignition system or gas supply. In that case, it's better to reach out to an experienced HVAC technician for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, it means it is turning on and off frequently at short intervals rather than running in regular cycles like it is designed to do. This can result in inefficiency, higher energy bills and potential damage to your unit.

If you believe your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be exchanged regularly to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and be sure it is pointing in the right direction. Second, check your thermostat and make sure  it’s set right and the batteries are good.

If those two things don’t work, it’s smart to call experts like the crew at Smyth Air Conditioning. Prompt professional attention will help restore the proper functioning of your furnace and avoid more complications and high energy bills.

6. My Furnace Is Making a Humming Noise

Whenever your furnace is making a humming noise, it often is an indication of an issue with the electrical parts or the blower motor. Because of this, if you detect your furnace making a humming noise, it is crucial to take action.

If the noise persists, it is better that you  employ a professional HVAC technician.

7. My Furnace Makes Loud Noises

If your furnace is emitting a constant loud noise, it's important to deal with the issue right away to prevent further damage or potential safety hazards.  One common cause of this is a failing blower motor or fan, which can generate a grinding or screeching sound. Another potential cause is a loose or worn-out belt that may produce a squealing or rattling noise.

Due to the complexity of furnace systems and potential risks involved, it's safer to contact a heating and cooling specialist.

8. My Furnace Is Not Turning On

If your furnace refuses to turn on, make sure the thermostat is set to the preferred temperature, is in heating mode and the batteries are functioning. Then, verify that the circuit breaker or fuse controlling the furnace is functioning properly. If these basic checks don't address the problem, you can check the furnace's power switch or emergency shutoff switch to ensure they're in the "on" position and weren’t accidentally turned off.

If those steps don’t get the job done, contact a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

Like a a furnace that will not on at all, a furnace that isn’t igniting can be caused by a clogged air filter or a tripped circuit breaker. So, checking out the air filter and looking over your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting are a faulty igniter or malfunctioning flame sensor. Indications of these include the furnace continually making an attempt to ignite without success, no heat production or the furnace is making a burning or gas smell. Both of these issues can be simply solved by HVAC specialists like the team at Smyth Air Conditioning.